An official in the Uttarakhand Disaster Management Division said there were no reports of death, injury and even damage to structures.

"Reports so far, from all across the district, indicate nothing adverse. It was a mild event," said police-constable Parveen. He is also part of the State's disaster management set-up.

An earthquake of a magnitude of 5.5, with its epicenter in Rudraprayag, Uttarakhand, registered tremors as far away as Delhi, at around 8.49 last night.

People in Delhi saw wall hangings tremble but the shaking was also barely perceptible to several.

The earthquake registered a depth of nearly 30 km. Uttarakhand is among the States vulnerable to considerable damage from earthquakes, partly because of the several folds of mountains, the geology that eases the passage of tremors and a massive store of unreleased energy that's been building up over centuries.

Experts have frequently warned that a huge earthquake, greater than magnitude 8.0, is imminent in this region, though there's no saying when.

Several districts of Uttarakhand fall in Zone 4, or among the States in India that are at high seismic risk. Zone 5 is the highest on the seismic risk scale.